From 3e35d9918cbbc224f88da4dd19cd90b2cd4f765e Mon Sep 17 00:00:00 2001 From: Bruce Allan Date: Sat, 12 Jan 2013 07:25:22 +0000 Subject: [PATCH] e1000e: adjust PM QoS request It has been found that devices other than 82579 (a.k.a. e1000_pch2lan) suffer from dropped transactions on platforms with deep C-states when jumbo frames are enabled. For example, LOMs on ICH9- and ICH10-based platforms which recently had early-receive de-featured (for stability reasons) suffer from this. To resolve this for all devices, when jumbo frames are enabled set the PM QoS DMA latency request based on the size of the receive packet buffer less one full frame. Signed-off-by: Bruce Allan Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/e1000e/defines.h | 2 ++ drivers/net/ethernet/intel/e1000e/netdev.c | 32 +++++++++++---------- 2 files changed, 19 insertions(+), 15 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000e/defines.h b/drivers/net/ethernet/intel/e1000e/defines.h index 3b997194ac3b..c4587671dc73 100644 --- a/drivers/net/ethernet/intel/e1000e/defines.h +++ b/drivers/net/ethernet/intel/e1000e/defines.h @@ -393,6 +393,8 @@ #define E1000_PBA_8K 0x0008 /* 8KB */ #define E1000_PBA_16K 0x0010 /* 16KB */ +#define E1000_PBA_RXA_MASK 0xFFFF + #define E1000_PBS_16K E1000_PBA_16K /* Uncorrectable/correctable ECC Error counts and enable bits */ diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index e386e95102f4..46a38a4d8da5 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -3242,18 +3242,23 @@ static void e1000_configure_rx(struct e1000_adapter *adapter) rxcsum &= ~E1000_RXCSUM_TUOFL; ew32(RXCSUM, rxcsum); - if (adapter->hw.mac.type == e1000_pch2lan) { - /* With jumbo frames, excessive C-state transition - * latencies result in dropped transactions. - */ - if (adapter->netdev->mtu > ETH_DATA_LEN) { + /* With jumbo frames, excessive C-state transition latencies result + * in dropped transactions. + */ + if (adapter->netdev->mtu > ETH_DATA_LEN) { + u32 lat = + ((er32(PBA) & E1000_PBA_RXA_MASK) * 1024 - + adapter->max_frame_size) * 8 / 1000; + + if (adapter->flags & FLAG_IS_ICH) { u32 rxdctl = er32(RXDCTL(0)); ew32(RXDCTL(0), rxdctl | 0x3); - pm_qos_update_request(&adapter->netdev->pm_qos_req, 55); - } else { - pm_qos_update_request(&adapter->netdev->pm_qos_req, - PM_QOS_DEFAULT_VALUE); } + + pm_qos_update_request(&adapter->netdev->pm_qos_req, lat); + } else { + pm_qos_update_request(&adapter->netdev->pm_qos_req, + PM_QOS_DEFAULT_VALUE); } /* Enable Receives */ @@ -4281,10 +4286,8 @@ static int e1000_open(struct net_device *netdev) e1000_update_mng_vlan(adapter); /* DMA latency requirement to workaround jumbo issue */ - if (adapter->hw.mac.type == e1000_pch2lan) - pm_qos_add_request(&adapter->netdev->pm_qos_req, - PM_QOS_CPU_DMA_LATENCY, - PM_QOS_DEFAULT_VALUE); + pm_qos_add_request(&adapter->netdev->pm_qos_req, PM_QOS_CPU_DMA_LATENCY, + PM_QOS_DEFAULT_VALUE); /* before we allocate an interrupt, we must be ready to handle it. * Setting DEBUG_SHIRQ in the kernel makes it fire an interrupt @@ -4392,8 +4395,7 @@ static int e1000_close(struct net_device *netdev) !test_bit(__E1000_TESTING, &adapter->state)) e1000e_release_hw_control(adapter); - if (adapter->hw.mac.type == e1000_pch2lan) - pm_qos_remove_request(&adapter->netdev->pm_qos_req); + pm_qos_remove_request(&adapter->netdev->pm_qos_req); pm_runtime_put_sync(&pdev->dev);